support sha256 in hex as secondary key when calling get_table_rows

[venediktov]

This is related to pull request #4053
We have a contract similar to dice.cpp where table has non-unique index checksum256 uuid column and
we need to retrieve all entries matching that fields as it serves a UUID of a handshake session .

 struct message {
            uint64_t id{};
            account_name from{};
            account_name to{};
            checksum256 uuid{};
            std::string data;

            uint64_t primary_key() const { return id; }
            account_name by_account_from() const { return from; }
            account_name by_account_to() const { return to; }
            key256 by_uuid() const { return checksum256_to_key256(uuid); }
            EOSLIB_SERIALIZE(message, (id)(from)(to)(uuid)(data))
        };

@taokayan , @heifner - Please let me know if you think it's valid case to pass sha256 hex string to get_table_rows

Use case

cleos get table account account messages --key-type sha256 --index 4 -L c01b39c7a35ccc3b081a3e83d2c71fa9a767ebfeb45c69f08e17dfe3ef375a7b

[heifner]

What error do you get if you use: cleos get table account account messages --key-type i256 --index 4 -L c01b39c7a35ccc3b081a3e83d2c71fa9a767ebfeb45c69f08e17dfe3ef375a7b

[heifner]

This include file not needed.

[venediktov]

agree ! leftover from last use of from_hex( const fc::string& hex_str, char* out_data, size_t out_data_len ) , thank you!

[heifner]

&p not used in lambda

[venediktov]

yes, left over from earlier code I used it for logging, will remove it.

i256 assumes the string is in decimal 32 bytes numeric string not in hex , but also when I converted sha256 hex 64 bytes key to decimal 32 and used it with i256 it did not find my rows.

[venediktov]

I will test it again with i256 and let you know @heifner , thank you!

[venediktov]

python -c 'print str(int("c01b39c7a35ccc3b081a3e83d2c71fa9a767ebfeb45c69f08e17dfe3ef375a7b", 16))'
86892170580511395102392104225515491945535356631148603271263139179137605261947

[venediktov]

@heifner , I will use that decimal again to test if i256 works .

[gustavomick]

@heifner not sure if is a issue, or a miss config from my side, but if you have a sec, please check https://eosio.stackexchange.com/questions/3219/how-to-properly-use-cleos-get-table-with-key-type-sha256-secondary-index-fa

[gustavomick]

@venediktov is this working for you on 1.4.+ ? could you provide me with an example using get table? thanks

[venediktov]

@gustavomick I had multiple examples that worked unfortunately due to NDA with a client I can't share it here , we only used 1.3 though

how do you initialize your _hasher in your class _hasher{_self,self} ?
can you send more code that shows _hasher{code, scope} initialization ?

[venediktov]

@gustavomick , I found your issue please see a change needed for your checksum256_to_sha256

static key256 checksum256_to_sha256(const checksum256 &hash)
{
    const uint128_t *p128 = reinterpret_cast<const uint128_t *>(&hash);
    key256 k;
    k.data()[0] = p128[0];
    k.data()[1] = p128[1];
    return k;
}

I justs tested it worked with this command

cleos get table testchecksum testchecksum  hasher --index 2 --key-type sha256 -L45d944598dccadd8c5a56e29c9786f05fa4b23402b735de61ce2912c86bac4de  -U45d944598dccadd8c5a56e29c9786f05fa4b23402b735de61ce2912c86bac4df